linux.git/tools/perf/util/annotate.h, branch v6.9

perf annotate: Add comments in the data structures

2024-03-07T04:25:48+00:00

Reviewed-by: Ian Rogers 
Reviewed-by: Arnaldo Carvalho de Melo 
Tested-by: Arnaldo Carvalho de Melo 
Cc: Andi Kleen 
Signed-off-by: Namhyung Kim 
Link: https://lore.kernel.org/r/20240304230815.1440583-5-namhyung@kernel.org

perf annotate: Remove sym_hist.addr[] array

2024-03-07T04:25:36+00:00

It's not used anymore and the code is coverted to use a hash map.  Now
sym_hist has a static size, so no need to have sizeof_sym_hist in the
struct annotated_source.

Reviewed-by: Ian Rogers 
Reviewed-by: Arnaldo Carvalho de Melo 
Tested-by: Arnaldo Carvalho de Melo 
Cc: Andi Kleen 
Signed-off-by: Namhyung Kim 
Link: https://lore.kernel.org/r/20240304230815.1440583-4-namhyung@kernel.org

perf annotate: Calculate instruction overhead using hashmap

2024-03-07T04:25:20+00:00

Use annotated_source.samples hashmap instead of addr array in the
struct sym_hist.

Reviewed-by: Ian Rogers 
Reviewed-by: Arnaldo Carvalho de Melo 
Tested-by: Arnaldo Carvalho de Melo 
Cc: Andi Kleen 
Signed-off-by: Namhyung Kim 
Link: https://lore.kernel.org/r/20240304230815.1440583-3-namhyung@kernel.org

perf annotate: Add a hashmap for symbol histogram

2024-03-07T04:24:55+00:00

Now symbol histogram uses an array to save per-offset sample counts.
But it wastes a lot of memory if the symbol has a few samples only.
Add a hashmap to save values only for actual samples.

For now, it has duplicate histogram (one in the existing array and
another in the new hash map).  Once it can convert to use the hash
in all places, we can get rid of the array later.

Reviewed-by: Ian Rogers 
Reviewed-by: Arnaldo Carvalho de Melo 
Tested-by: Arnaldo Carvalho de Melo 
Cc: Andi Kleen 
Signed-off-by: Namhyung Kim 
Link: https://lore.kernel.org/r/20240304230815.1440583-2-namhyung@kernel.org

perf annotate-data: Support global variables

2024-01-22T20:08:20+00:00

Global variables are accessed using PC-relative address so it needs to
be handled separately.  The PC-rel addressing is detected by using
DWARF_REG_PC.  On x86, %rip register would be used.

The address can be calculated using the ip and offset in the
instruction.  But it should start from the next instruction so add
calculate_pcrel_addr() to do it properly.

But global variables defined in a different file would only have a
declaration which doesn't include a location list.  So it first tries
to get the type info using the address, and then looks up the variable
declarations using name.  The name of global variables should be get
from the symbol table.  The declaration would have the type info.

So extend find_var_type() to take both address and name for global
variables.

The stat is now looks like:

  Annotate data type stats:
  total 294, ok 153 (52.0%), bad 141 (48.0%)
  -----------------------------------------------------------
          30 : no_sym
          32 : no_mem_ops
          61 : no_var
          10 : no_typeinfo
           8 : bad_offset

Reviewed-by: Ian Rogers 
Cc: Stephane Eranian 
Cc: Masami Hiramatsu 
Link: https://lore.kernel.org/r/20240117062657.985479-7-namhyung@kernel.org
Signed-off-by: Namhyung Kim

perf annotate-data: Handle array style accesses

2024-01-22T20:08:19+00:00

On x86, instructions for array access often looks like below.

  mov  0x1234(%rax,%rbx,8), %rcx

Usually the first register holds the type information and the second one
has the index.  And the current code only looks up a variable for the
first register.  But it's possible to be in the other way around so it
needs to check the second register if the first one failed.

The stat changed like this.

  Annotate data type stats:
  total 294, ok 148 (50.3%), bad 146 (49.7%)
  -----------------------------------------------------------
          30 : no_sym
          32 : no_mem_ops
          66 : no_var
          10 : no_typeinfo
           8 : bad_offset

Reviewed-by: Ian Rogers 
Cc: Stephane Eranian 
Cc: Masami Hiramatsu 
Link: https://lore.kernel.org/r/20240117062657.985479-4-namhyung@kernel.org
Signed-off-by: Namhyung Kim

perf annotate: Add --insn-stat option for debugging

2023-12-24T01:40:17+00:00

This is for a debugging purpose.  It'd be useful to see per-instrucion
level success/failure stats.

  $ perf annotate --data-type --insn-stat
  Annotate Instruction stats
  total 264, ok 143 (54.2%), bad 121 (45.8%)

    Name      :  Good   Bad
  -----------------------------------------------------------
    movq      :    45    31
    movl      :    22    11
    popq      :     0    19
    cmpl      :    16     3
    addq      :     8     7
    cmpq      :    11     3
    cmpxchgl  :     3     7
    cmpxchgq  :     8     0
    incl      :     3     3
    movzbl    :     4     2
    incq      :     4     2
    decl      :     6     0
    ...

Committer notes:

So these are about being able to find the type for accesses from these
instructions, we should improve the naming, but it is for debugging, we
can improve this later:

  @@ -3726,6 +3759,10 @@ struct annotated_data_type *hist_entry__get_data_type(struct hist_entry *he)
                          continue;

                  mem_type = find_data_type(ms, ip, op_loc->reg, op_loc->offset);
  +               if (mem_type)
  +                       istat->good++;
  +               else
  +                       istat->bad++;

Signed-off-by: Namhyung Kim 
Cc: Adrian Hunter 
Cc: Ian Rogers 
Cc: Ingo Molnar 
Cc: Jiri Olsa 
Cc: Linus Torvalds 
Cc: Masami Hiramatsu 
Cc: Peter Zijlstra 
Cc: Stephane Eranian 
Cc: linux-toolchains@vger.kernel.org
Cc: linux-trace-devel@vger.kernel.org
Link: https://lore.kernel.org/r/20231213001323.718046-18-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo

perf annotate: Implement hist_entry__get_data_type()

2023-12-24T01:39:42+00:00

It's the function to find out the type info from the given sample data
and will be called from the hist_entry sort logic when 'type' sort key
is used.

It first calls objdump to disassemble the instructions and figure out
information about memory access at the location.  Maybe we can do it
better by analyzing the instruction directly, but I'll leave it for
later work.

The memory access is determined by checking instruction operands to
have "(" and then extract register name and offset.  It'll return NULL
if no data type is found.

Signed-off-by: Namhyung Kim 
Cc: Adrian Hunter 
Cc: Ian Rogers 
Cc: Ingo Molnar 
Cc: Jiri Olsa 
Cc: Linus Torvalds 
Cc: Masami Hiramatsu 
Cc: Peter Zijlstra 
Cc: Stephane Eranian 
Cc: linux-toolchains@vger.kernel.org
Cc: linux-trace-devel@vger.kernel.org
Link: https://lore.kernel.org/r/20231213001323.718046-8-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo

perf annotate: Add annotate_get_insn_location()

2023-12-24T01:39:42+00:00

The annotate_get_insn_location() is to get the detailed information of
instruction locations like registers and offset.  It has source and
target operands locations in an array.  Each operand can have a register
and an offset.  The offset is meaningful when mem_ref flag is set.

Signed-off-by: Namhyung Kim 
Cc: Adrian Hunter 
Cc: Ian Rogers 
Cc: Ingo Molnar 
Cc: Jiri Olsa 
Cc: Linus Torvalds 
Cc: Masami Hiramatsu 
Cc: Peter Zijlstra 
Cc: Stephane Eranian 
Cc: linux-toolchains@vger.kernel.org
Cc: linux-trace-devel@vger.kernel.org
Link: https://lore.kernel.org/r/20231213001323.718046-7-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo

perf annotate: Factor out evsel__get_arch()

2023-12-24T01:39:42+00:00

The evsel__get_arch() is to get architecture info from the environment.

It'll be used by other places later so let's factor it out.

Also add arch__is() to check the arch info by name.

Committer notes:

"get" is usually associated with refcounting, so we better rename this
at some point to a better name.

Signed-off-by: Namhyung Kim 
Cc: Adrian Hunter 
Cc: Ian Rogers 
Cc: Ingo Molnar 
Cc: Jiri Olsa 
Cc: Linus Torvalds 
Cc: Masami Hiramatsu 
Cc: Peter Zijlstra 
Cc: Stephane Eranian 
Cc: linux-toolchains@vger.kernel.org
Cc: linux-trace-devel@vger.kernel.org
Link: https://lore.kernel.org/r/20231213001323.718046-6-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo